Composite can with quick-opening lap seam



Dec. 25, 1956 H. A. BERGs'rRoM 2,775,395

COMPOSITE CAN WITH QUICK-OPENING LAP SEAM Filed March 22, 1954 INVENTOR 3 HAROLD A. BERGsTRoM BYZam, M L

ATTORNEYS United States Patent COlVIPOSITE CAN WITH QUICK-OPENING LAP SEAM Harold A. Bergstrom, Van Wert, Ohio, assignor to Continental Can Company, Inc., New York, N. Y., a corporation of New York Application March 22, 1954, Serial No. 417,865

6 Claims. (Cl. 229-51) The following specification deals with a composite can having a quick-opening lapped side seam. Such cans are particularly adapted for the merchandising of foodstuffs and other materials. They are so called because they are composed of a sidewall of pulp orpaper board,`

while the tops and bottoms are made of sheet metal according to the usual practice.

At the present time, these cans are used for packaging storage, some internal pressure develops in the goodsV and isexerted on the inner Walls of the can. vAny effort to open the can at a selected point results in the sudden l release of the pressure at that point. This is equalized by pressure from the rest of the contents. As a result the material nearest the opening may be forced out of the can resulting in considerable distortion of the shape of the goods.

Raised biscuits to the number of perhaps 10, are cus If the side wall of thev tomarily packed in such a can. can is punctured in the opening movement, the biscuit opposite the opening will be forced out of` shape by the internal pressure as above described. The remaining contents will be distorted in varying amounts. It is an object of my invention to provide a composite can having at least two plies of material such as paper orA paper board so designed as to permit simultaneous opening over the entire length of the side wall. This serves to release the internal pressure for the full height of the can so thatall of the contained articles retain their original shape. n

A further objectof the invention is to provide a can of this nature `which maybe opened by the fingers and without the use ofanyparticular implements.

NItV is a still furtherobject of theinvention to provide a canin which the lapped side seamis utilized as the point at which the opening is executed simultaneously over the length of the can. y K

' Among-the objects of my invention is to utilizeA tlie transparent or printed paper label which is wrapped around the side wall of the can as a means for facilitating the extensive opening for the discharge of the contents.

Other objects of the invention will be apparent from the following description of the preferred form as illustrated in the accompanying drawing in which:

Fig. 1 is the improved paper blank with two plies and adhesive across the ends;

Fig. 5 is a perspective `view of the completed can with a metal top and with the outer ply torn to provide a ap;

Fig. 6 is a fragmentary vertical cross-section on the line 6-6 of Fig. 5;

Fig. 7 is a fragmentary cross-section of modified form, a single ply wall with a ap instead of the coextensive label or wrapper and p Fig. 8 is a similar view of the ap bent up preparatory to opening.

The invention as illustrated inthe drawings is carried out by providing a side wall having a ber or paper board layer or inner ply with an associated outer portion which may or may not be coextensive with the inner ply, but which will serve as the means for opening up the side seam simultaneously over its length. Y

Thus in Fig. l I have shown a blank 11 for constructing a sidewall. This blank consists of an inner ply 12 of fiber or paper board of suitable strength to withstand` contents. The inside surface of this ply can be lined with aluminum foil, parchment, glassine, plastic lm or any similar protecting medium.

The outer ply 13 is much thinner than the inner ply 12. Thek outer plytmay consist of a layer of paper on which a design has been printed and which may be given a glazed surface. The outer-ply 13 may be transparent to permit the display of a design appearing on the inner ply. The outer ply also has a denite function in reinforcing the inner ply. v

The ends 14 and 15 of the inner ply 12 are each coated on the outer side with a' narrow strip of adhesive 16, 16.

t The outer` ply 13 is attached to the inner ply 12 at the ends only and by means of the adhesive portion 16, 16.

The outer ply 13 lies closely against the outer surface of` the `inner ply 12. To facilitate the opening of the can the outer ply is scored transversely or otherwise somewhat weakened along the line 17 as shown on Fig. 1 and at the points indicated on Figs. 2 and 3. `It is also scored longitudinally along the side edges as indicated at 17a.

By applying an adhesive strip 18 across outside surface of the outer ply 13 at the end 14, the `opposite end 15 may be lapped over the adhesive part and a side seam produced. The adhesive 18 `is thermoplastic and the seamy can be made by a momentary application of heat and pressure.

p AV protective coating 19 is then applied over the exposed edge of the inner ply at the end 14, and this extends to the inner surface of the opposite overlapped end so Yas to seal the side seam and prevent deterioration or losscaused by the nature of the contents of the can.

KA top 20 preferably of metal is rolled over the side edges of the can body and formed into a bead 21 as illustrated in Figs. 5 and 6. It will be apparent that this bead also overliesthe outer ply `13 along its side edges.

The bottom 21, also `ofsheet metal, is likewise beaded over the lower side edge ofthe can body.

In order to facilitate the `continued opening of the can from the side seam, the inner ply 12 is lightly scored as shown at 22, 22 on lines within and parallel to the side edges starting from the overlying end 15. This scoring is carried out on the inner surface of the inner ply 12 and for a depth of approximately one fourth the thickness of the paper board. The scoring should extend about one half the length of the blank. In order to seal the can at this area, a protective coating 23 of enamel, lacquer or other material, is applied over the scored lines.

The mode of simultaneously opening this can throughout the length of the side seam is illustrated in Figs. 4 and 5. By tearing the outer thin ply 13 along the lines 17 and 17a, it forms a flap 24 which may be bent back to the overlapped side seam formed by the ends 14 and 15. At this point an outward pull on the flap 24 will apply stress Patented Dec. 25, 1956l and` flap 24' areV thus pulled' away from they adhesive` 16 holding ap 15 to end 14 or if this adhesive does not let go, the paperboard 12 to which itis adhered will shear internally. to' open upjtheA- entire sideseam.l Thisiopeninggoperati'on occurs substantially simultaneouslyrovertlre len'gtliof the side seam; Even iftthe movement is started,

at one end,-` it will bepractically completedthrougliout the length of the side seam and to the' oppositeendbefore any part of'the contents are exposed.v v

In the opening movement,the sealing coating` i9 is also torn apart'.

By this means there is a. completeabsence` oflocalized release of pressureon the contents: There is'therefore no distortion resulting from thek release of thetinternal pressure; Y

Since the overlappingvendllSof the inner ply has been scored along the lines 22, 22, theopening movementcan be readily carried out for substantially half the lcircumference of the pan. As soon as the flap; 24' and` the-end 15 'have :been rolled backto the desiredextent; the package may be inverted and the contentswill dropout freely.

It will'beapparent that the ap 24` neednot becoex'-` tensive withthe sideA wall. Itis` only necessary that it provide a finger hold along the side. seam and outer edge 15 of the inner ply. It is therefore possible. to apply this inventionv to a single ply container. This has been illustrated in Figs. 7 and 8, in which thel end 15 overlaps the end 14; as above, described. However, the end 14`car.- ries an adhesive iiap 25 of limited length only. The flap 25 is attached by adhesive strip 18 to the overlying end 15 of the inner ply 12.

In use, the ap 25,1ies closely. parallel to the end,V 14 of the inner ply as shown in Fig.Y 7. When, however, it is desired to open thecan, the flap 25`is raised as shown in Fig.v 8 by theoperators fingers, and a sharp, upward pull serves to start the opening movement which, may be immediately completed over the entire length of the end` 15. Thefull opening will of course be the same as is shown in Fig, 5. y

The above.description illustratesv thev preferred form of theinvention without, however, limitingthe. variations possible in materials, proportions andminor details other than as indicated bythe scope ofthe appended claims.

What I claim is:

1. A composite side-opening can with a top and a bottom and having, a side wall of paper board or like material comprising an inner ply and an outer ply coextensive therewith, ,said plies being joined together at their ends only, and overlapping at. the end of`a single convolution, the outer ply at that point beingV cemented' to the inner ply of the opposite end toform a. continuous four-ply side seam, the outer ply beingtransversely scored.V at a point inwardly ofrthe cemented end'for guided severance and parting yof the seam'between the severed endof the outer ply andthe underlying end offthe inner ply.

2. A- composite side-opening, can withj a top andV a bottom having a side. wall ofipap'er board` or like. material comprising an inner plyand an outer ply coextensive therewith, said plies being joined .together attheir ends only,V

and overlapping at the' end of a single convolutiomthe outer ply at that point being cemented to the inner ply oftheopposite` end to forma-continuousl side seam, saidy outer ply being transversely scored at an intermediate point to form a flap for splitting the side seam between the plies of the underlying end.

3. A composite side-opening can with circular top and bottom members and having a side wall of paper board or like material comprising an inner` ply and an outer ply coextensive therewith, said plies being joined together at their ends only, the outer ply at one end being cemented to the inner ply of the opposite end to form a continuous four-ply side seam, saidouter ply. being transversely scored at an intermediate point to form a flap extending for theV full length of the side seam between said top and bottom members for splitting the seam between the plies of the underlying end.

4. A composite side-opening can with a side wall and a top and a bottom each beaded over the lateral edges of the sidewall, said side wall comprising'an inner ply and a coextensive outer ply, said plies being joined together at their ends only, and the ends being overlapped at the end' of a single convolution and cemented together to form a continuous separable side seam, the outer ply being transversely scored at an intermediate point and lightly scored from that point tothe seam along lines adjacent the beads of the top and bottom.

5. A composite side-opening can with a side wall and a top and a bottom each beaded over the lateral edges of the side wall, said side wall comprising an inner ply and a coextensiveouter ply, said plies being joined together at their ends only, and the ends being overlapped at the end of a single. convolution and cemented together to form` al continuous separablesideY seam, the outer ply being transversely scored at an intermediate point and lightly scoredvfrom that point to the seam along lines adjacent the beads of the top and bottom, and the inner ply at the'overlapping end beingscored alongy projections of the'said lines and adjacent the beads of the top and bot-V overlying the inner portion of'saidiseam, said outer ply` beingxtransversely scored` at an intermediate point to forma-iiap for splitting the side seambetween the pliesofv'thevunderlying end andV for tearing-theI sealing layer opposite the seam.

References Cited in the .file of this patent UNITED STATES PATENTS 67.9;171 Jones July 23, 1901 1,072,914 Comings Sept. 9, 1913 2,062,278 Vogt Nov. 24, 1936 2,150,207 Curriev Mar. 14, 1939 2,318,101 Rose May 4, 1943 2,608,341 Eckman Aug. 26,1952 2,695,847-

Fisher Nov. 30, 1954 

